1. Field of the Invention
The present invention relates to a television receiver including a tuner and a module for controlling the tuner.
2. Background Art
Examples of a television receiver having a tuner for receiving a television broadcast signal include a television set, a VCR (Video Cassette Recorder), a DVD (Digital Versatile Disk) recorder, an HDD (Hard Disk Drive) recorder, a composite device obtained by integrating at least two of the devices, and a simple receiver having no function of recording/reproducing a video image and sound. Tuners include a digital tuner for receiving a digital television broadcast signal, an analog tuner for receiving an analog television broadcast signal, and a digital/analog tuner for receiving both digital and analog television broadcast signals. There is a television receiver having a module for processing an IF (Intermediate Frequency) signal output from a tuner while controlling the tuner, and outputting a video signal and an audio signal.
A manufacturer of such a television receiver usually purchases a tuner from a tuner manufacturer, develops a module by the television receiver manufacturer itself, connects the tuner and the module to each other, and assembles the connected tuner and module into a receiver body. Since the specifications of tuners vary among manufactures, models, and the like, if the module cannot perform control according to the kind of a tuner, it is impossible to receive the television broadcast signal with high precision and output a video signal and an audio signal. Therefore, the television receiver manufacturer usually develops modules in accordance with the kinds of tuners used. To suppress the cost of development and manufacture of modules, a tuner used is limited to one model of one manufacturer.
However, due to lack of the number of tuners supplied or the like, there is a case that a plurality of kinds of tuners have to be alternatively used. In this case, conventionally, the circuit of a module is changed according to the kind of a tuner assembled. Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2004-507911 discloses a technique of replaceably assembling one tuner and a nonvolatile memory that stores control information adapted to the tuner into a chassis of a television receiver. However, in such method, due to a human error, there is a case that the tuner and the module or the nonvolatile memory are not matched correctly.
On the other hand, Japanese Unexamined Patent Application Publication No. 2001-309261 discloses a technique in which a personal computer performs data communication with a tuner via a capture card, makes the tuner receive a television broadcast signal of a frequency corresponding to a channel in any of countries, determines whether the level of an AFT (Auto Frequency Tuning) signal returned from the tuner is normal or not and, on the basis of the result, automatically determines a channel station which can be tuned, and the kind of the tuner corresponding to the country with which the tuner tunes. According to such method, however, the kind of the tuner being further detailed than the country, in which the manufacturer, model, and the like are different each other, cannot be automatically determined.